package com.park.gateway.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.cors.reactive.CorsUtils;
import org.springframework.web.server.WebFilter;
import reactor.core.publisher.Mono;

/**
 * @ClassName CorsConfig
 * @Description 跨域配置
 * @Date 2023/5/26 17:42
 * @Author huxiaohua
 */
@Configuration
public class CorsConfig {
    // 允许的请求头
    private static final String ALLOWED_HEADERS = "x-requested-with, authorization, Content-Type, Authorization, credential, X-XSRF-TOKEN, Session-Id, Session-Type";
    private static final String ALLOWED_METHODS = "GET, PUT, POST, DELETE, OPTIONS";
    private static final String ALLOWED_ORIGIN = "*";
    private static final String ALLOWED_EXPOSE = "*";
    private static final String MAX_AGE = "86400";

    @Bean
    public WebFilter corsFilter() {
        
        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest();
            if (CorsUtils.isCorsRequest(request)) {
                ServerHttpResponse response = exchange.getResponse();
                HttpHeaders headers = response.getHeaders();
                headers.add("Access-Control-Allow-Origin", ALLOWED_ORIGIN);
                //允许请求的方法;
                headers.add("Access-Control-Allow-Methods", ALLOWED_METHODS);

                headers.add("Access-Control-Max-Age", MAX_AGE);
                //允许什么请求头 *表示所有
                headers.add("Access-Control-Allow-Headers", ALLOWED_HEADERS);
                //配置前端js允许访问的自定义响应头
                headers.add("Access-Control-Expose-Headers", ALLOWED_EXPOSE);
                //允许后端服务跨域cookie传到前端
                headers.add("Access-Control-Allow-Credentials", "true");
                if (request.getMethod() == HttpMethod.OPTIONS) {

                    response.setStatusCode(HttpStatus.OK);

                    return Mono.empty();

                }
            }
            return chain.filter(exchange);
        };
    }
}
